Change of nutrients and botanical composition of mixed Lolium perenne ╋Trifolium repens grasslands under long-term grazing and mowing utilizations

Effect of mowing(M), mowing + grazing(M+G), continuous grazing(CG) and rotational grazing(RG) on the nutrients of soils and herbages, and the botanical composition of mixed Lolium perenne+Trifolium repens pasture on Guizhou plateau were quantity monitored and analyzed, which would provide some practical basis for the grassland sustainable utilization. The results showed that, the contents of the nutrition in soil varied largely, the soil of CG grassland was severely acidification. For herbage, contents of Ca in M grassland, P in RG grassland, Cu in M and M+G grassland were higher than the other, and content of Mg in CG was lowest; while the nutritive values of four treatments had no significant difference. The number of tillers of L.perenne were RGM+GM=CG, and the tiller weight were M=M+GCG=RG; while the density and weight of T.repens stolon were M=RGM+G and CG. The number of species were CGM=M+GRG. The community structure of CG grassland was complex and dominated by Eragrostis pilosa, M grassland dominated by T.repens+Taraxacum officinale+Artemisia lactiflora; while the community structure of M+G and RG grassland were simple and dominated by L.perenne+T.repens. Thus, ultilization method of M+G and RG were more suitable for long term grassland utilization in research area.